feat(media): manage client and project thumbnails

src/pages/Clients.tsx

@@ -190,7 +190,11 @@ export default function Clients() {
                       <div className="flex items-start justify-between gap-3">
                         <div className="flex min-w-0 items-center gap-3">
                           <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-xl bg-slate-100 text-sm font-semibold text-slate-700 dark:bg-slate-700 dark:text-slate-200">
-                            {client.name.trim().charAt(0).toUpperCase() || "C"}
+                            {client.thumbnail ? (
+                              <img src={client.thumbnail} alt={client.name} className="h-full w-full rounded-xl object-cover" />
+                            ) : (
+                              client.name.trim().charAt(0).toUpperCase() || "C"
+                            )}
                           </div>
                           <div className="min-w-0">
                             <CardTitle className="truncate text-base text-slate-900 dark:text-white">{client.name}</CardTitle>